1. Field of the Invention
The present invention relates to smart cards, and more specifically to the manufacturing of a smart card with an antenna.
2. Description of Related Art
In conventional methods of manufacturing a smart card with an antenna, a smart card containing at least one metal winding is first manufactured. The metal winding is located some distance from the opposed faces of the card and the ends of the winding form electrical connection pads. A cavity is milled in the card to expose the connection pads, and then an electronic chip is fixed in the cavity and connected to the exposed pads. In order to mill the cavity, the milling tool is made to penetrate the card step-by-step and is withdrawn between steps in order to allow a visual inspection to determine if the connection pads have been exposed. By repeating this process, the desired cavities are formed in a series of smart cards.
Because the smart cards do not always have the same thickness, the typical antenna has a thickness of 35 or 70 microns, and the antenna is not always placed at the same distance from the faces of the card, the machining of cavities in a series of cards produces a high percentage of cards in which the pads of the antenna are not exposed or are completely machined (i.e., destroyed). Obviously, such incorrectly machined cards must be rejected. To limit the number of cards that are rejected, the operator must closely monitor the machining process to insure that the cavity is being correctly produced in each card, and must frequently carry out the repeated machining and inspection operations described above. The required machining time and high rejection rate cause conventional methods of manufacturing smart cards to have low productivity and high manufacturing costs.